American Institute of Certified Planners (AICP) Practice Exam

The correct answer is San Francisco. In the early 20th century, San Francisco was at the forefront of adopting zoning regulations aimed at managing land use, particularly concerning "obnoxious uses" such as factories, junkyards, and other potentially disruptive activities that could affect residential areas. The city's approach set a precedent for land use planning and zoning across the United States.

The significance of San Francisco's actions lies in how they influenced the broader adoption of zoning practices that separated incompatible land uses to enhance public health, safety, and welfare. This was in line with the progressive reform movements of the time, which aimed to reduce the negative impacts of urbanization and industrialization on residents.

Other cities may have had zoning ordinances or regulations in place later, but San Francisco's early adoption of restrictions directly addressing obnoxious uses made it a pioneering example in the development of land use planning.